I just got my wife to make me something that fits over the camera and over my head , it looks a bit silly from a third person perspective as it looks like my head is in a sausage but there is no cloth flapping around in the wind either.

It really does not matter what you use as long as it blocks out the light so you can see the screen to focus

I definitely think a dark cloth is important, particularly in bright sunlight, where the black layer helps seeing the ground glass. A white sheet or shirt, or even a black tee shirt as some use doesn't give the same blocking out of light. The white layer to the outside helps reflect light and heat away from the camera. I mad my own out of black cotton and white sheet, about a metre square, at a fraction the cost of a commercial one; it's done me for years.

For what it's worth, I ended up buying a BTZS focus cloth. There's no argument that it's expensive but when you're struggling to see enough detail on the ground glass you really appreciate the complete blockout of ambient light as well as the convenience.

Some of my LF gear is done very much on the cheap, but I decided to splash out on a nice focus cloth Although I'm intrigued by andrewch59's idea of using a jumper; that's quite clever!

I pass on to you some erstwhile discoveries from my experience with BTZS viewing hoods in ioth 4x5 and 8x10 sizes. be sure to turn them inside out and air them. Also wipe them down periodically with a nioce soft cloth — due to the design they can get steamy and sweaty, particularly in hot, humid conditions.

It can be embarrassing when they get whiffy and it dawns on you that it is your own BO you are experiencing.

Walter Glover

"Photography was not a bastard left by science on the doorstep of art, but a legitimate child of the Western pictorial tradition." —Robert Galassi